To provide a camera apparatus which is inexpensive, is simple in structure and is installed in all places to photograph persons intruding into monitor regions.

A shutter activating mechanism 10 is built to a film housing box 6 which houses a film 2 with a lens and is provided with a photographing hole 8 for causing a lens portion 4 thereof to verge outside and a mounting hole 9 opposite to a shutter button 5. The shutter activating mechanism 10 has a shutter activating machine 12 which abuts at its one end on the shutter button and is projected a its other end to the outside of the film housing box through the mounting hole, an elastic member 13 which imparts the activating habit of the shutter button to the shutter activating member and a locking member 15 which holds the shutter activating member in the non-activating position of the shutter button by overcoming the elastic force of the elastic member by being held between the outer flank of the film housing box and the shutter activating member. The other end of a detecting wire 16 connected at its one end to the locking member 15 is fixed to the monitor region so as to creep along the region.